From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 68F94C04AB6 for ; Fri, 31 May 2019 19:25:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3BE7126E4A for ; Fri, 31 May 2019 19:25:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727395AbfEaTZF (ORCPT ); Fri, 31 May 2019 15:25:05 -0400 Received: from gateway32.websitewelcome.com ([192.185.145.171]:24589 "EHLO gateway32.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727085AbfEaTZF (ORCPT ); Fri, 31 May 2019 15:25:05 -0400 Received: from cm13.websitewelcome.com (cm13.websitewelcome.com [100.42.49.6]) by gateway32.websitewelcome.com (Postfix) with ESMTP id 0F23410293A5 for ; Fri, 31 May 2019 14:25:04 -0500 (CDT) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id Wn9Eh49quYTGMWn9Eh3BQY; Fri, 31 May 2019 14:25:04 -0500 X-Authority-Reason: nr=8 Received: from [189.250.123.250] (port=52648 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.91) (envelope-from ) id 1hWn93-003OqT-R2; Fri, 31 May 2019 14:25:02 -0500 Date: Fri, 31 May 2019 14:24:53 -0500 From: "Gustavo A. R. Silva" To: Paolo Bonzini , Radim =?utf-8?B?S3LEjW3DocWZ?= Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH] KVM: irqchip: Use struct_size() in kzalloc() Message-ID: <20190531192453.GA13536@embeddedor> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.9.4 (2018-02-28) X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - gator4166.hostgator.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - embeddedor.com X-BWhitelist: no X-Source-IP: 189.250.123.250 X-Source-L: No X-Exim-ID: 1hWn93-003OqT-R2 X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.250.123.250]:52648 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 4 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org One of the more common cases of allocation size calculations is finding the size of a structure that has a zero-sized array at the end, along with memory for some number of elements for that array. For example: struct foo { int stuff; struct boo entry[]; }; instance = kzalloc(sizeof(struct foo) + count * sizeof(struct boo), GFP_KERNEL); Instead of leaving these open-coded and prone to type mistakes, we can now use the new struct_size() helper: instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL); This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva --- virt/kvm/irqchip.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/virt/kvm/irqchip.c b/virt/kvm/irqchip.c index 79e59e4fa3dc..f8be6a3d1aa6 100644 --- a/virt/kvm/irqchip.c +++ b/virt/kvm/irqchip.c @@ -196,9 +196,7 @@ int kvm_set_irq_routing(struct kvm *kvm, nr_rt_entries += 1; - new = kzalloc(sizeof(*new) + (nr_rt_entries * sizeof(struct hlist_head)), - GFP_KERNEL_ACCOUNT); - + new = kzalloc(struct_size(new, map, nr_rt_entries), GFP_KERNEL_ACCOUNT); if (!new) return -ENOMEM; -- 2.21.0